1. Field of the Invention
The present disclosure relates to an eraser device, more particularly to an eraser wheel assembly structure.
2. Description of the Related Art
Please refer to FIGS. 6 and 7 which show an eraser wheel 91 and a shell cover 92 adapted to fasten the eraser wheel 91 in conventional technology. The eraser wheel 91 can be driven to rotate by a grinding tool (not shown in FIGS. 6 and 7), to grind and remove an adhesive coating layer, such as paint. The eraser wheel 91 has a plurality of glue removing blocks 911 disposed on a surface thereof and arranged in interval. The plurality of glue removing blocks 911 have the same shape and each is in a straight shape which has a width enlarged from inside to outside. The plurality of glue removing blocks 911 are arranged radially and annularly. The eraser wheel 91 has a plurality of protruding pins 912 disposed on other side thereof. Each protruding pin 912 has a wider blocking part 913 at a top thereof. The shell cover 92 has a groove part 921 formed on a side thereof, and an annular wall 922 formed at a peripheral edge of the groove part 921 thereof. A plurality of through-holes 923 are formed on the groove part 921 inside the annular wall 922.
The eraser wheel 91 is assembled into the groove part 921 of the shell cover 92 by placing the side on which the protruding pins 912 are disposed, and inserting the protruding pins 912 through the through holes 923 and making the blocking parts 913 be blocked at step parts 924. After assembly, the peripheral edge 914 of the eraser wheel 91 is tightly attached with the inner surface 925 of the annular wall 922, the eraser wheel 91 can be driven to rotate by the plurality of protruding pins 912 inserted in the through-holes 923 during rotation of the shell cover 92 driven by the grinding tool, so as to grind and remove the glue.
The eraser wheel 91 is made from flexible material and has a hardness falling within a score range of 50 to 60 in Shore hardness Type A for facilitating to remove the glue, However, while the eraser wheel 91 is being rotated to remove glue, the part of the eraser wheel 91 tightly attached with the position being removed glue is pressed and deformed to be flatter in an axial direction and wider in a radial direction. Particularly, as shown in FIG. 7, while removing glue at a rough place, the peripheral edge 914 of the eraser wheel 91 is easily squeezed out of the annular wall 922 because of aforesaid deformation, so that the eraser wheel 91 is axially moved out of the shell cover 92 and it further causes the blocking part 913 of the protruding pin 912 to escape from the step part 924, and the protruding pins 912 are pulled out of the through holes 923 and, as a result, the eraser wheel 91 is escaped from the shell cover 92. While the eraser wheel 91 is escaped from the shell cover 92, the plurality of glue removing blocks 911 cannot be uniformly in contact with the place being removed glue, so the user must stop the glue-removing action and manually press the eraser wheel 91 to lock the blocking parts 913 in the step parts 924 again. At this time, as the glue-removing action of the eraser wheel 91 is stopped, the peripheral edge 914 held on the annular wall 922 is not back to its former position, the user must manually press the peripheral edge 914 back to its former position in the groove part 921, but the user's operation must be interrupted.
Please refer to FIG. 8 which shows other conventional eraser wheel 93. A main difference between the eraser wheel 93 and the eraser wheel 91 is that the eraser wheel 93 has a plurality of glue removing blocks 932 and 933 respectively formed on wide root parts 931 thereof, inside-outside staggered, and arranged in interval. Compared with the eraser wheel 91, the glue removing blocks 932 and 933 of the eraser wheel 93 have smaller areas in tight contact with the working surface during glue-removing operation, so the deformation of the peripheral edge 934 can be reduced to decrease the times of escapes of the eraser wheel 93 from the shell cover 92. However, the escape of the eraser wheel 93 from the shell cover 92 cannot be avoided completely, and reduced tight-contact areas between the working surface and the glue removing blocks 932 and 933 also cause a poor glue-removing effect